From a quick glance it appears that Webmin isnt needed on the E-Smith server. If Im right, Webmin allows you to configure the server; users, samba file shares etc. These things are already taken care of by the E-Smith web based manager. Some of the other things that Webmin appears to do may be useful, but I suspect not. E-Smith is a pretty lightweight server, and any required user configuration is already provided.
Im not saying you shouldnt use it - Im just saying you probably dont need to.
Thanks for the post.